1. Field of the Invention
This invention relates to apparatus for driving piles by the stroke of a hammer in the form of a ram or dropweight.
2. Description of the Prior Art
The specification of British Pat. No. 1,168,547 describes a pile driving apparatus which has resilient impact transmitting buffer means in the path of travel of the hammer for transmitting the impact of the hammer stroke to a pile, conveniently through a pile cap or anvil on the top of the pile. The resilient impact transmitting buffer means comprises precompressed gas in a closed chamber and the stroke energy of the hammer in transmitted via the gas and a strike cap to the pile, the strike cap being supported in, and projecting from the chamber. The precompressed gas is further compressed on impact enabling the minimum force required to overcome the ground resistance, which opposes penetration of the pile, to be directly available under the impact, and smoothing out force peaks so that the maximum impact force does not exceed the force which causes damage to the pile.